"Variable variables"의 두 판 사이의 차이

2020년 11월 2일 (월) 02:35 기준 최신판

greeting="Hello World"
ref="greeting"
echo ${!ref}
# Hello World

greeting="Hello World"
ref="greeting"
eval echo \$$ref
# Hello World

greeting="Hello World"
ref="greeting"
eval result=\$$ref
echo $result
# Hello World

greeting="Hello World"
r1="greet"
r2="ing"
eval echo \$"$r1$r2"

$greeting = "Hello World";
$ref= "greeting";
echo $$ref;
// Hello World

$greeting = "Hello World";
$r1 = "greet";
$r2 = "ing";
echo ${$r1.$r2};
// Hello World

@@ 1번째 줄: / 1번째 줄: @@
 [[category: variable]]
 [[category: string]]
+==개요==
 ;Variable variables
 ;변수 변수
+*변수값을 변수명으로 사용
 ==Bash==
 [[category: Bash]]
-<source lang='Bash'>
+<syntaxhighlight lang='Bash'>
 greeting="Hello World"
-variable_name="greeting"
+ref="greeting"
-eval echo \$$variable_name
+echo ${!ref}
 # Hello World
-</source>
+</syntaxhighlight>
-<source lang='Bash'>
+<syntaxhighlight lang='Bash'>
 greeting="Hello World"
-variable_name="greeting"
+ref="greeting"
-eval result=\$$variable_name
+eval echo \$$ref
+# Hello World
+</syntaxhighlight>
+<syntaxhighlight lang='Bash'>
+greeting="Hello World"
+ref="greeting"
+eval result=\$$ref
 echo $result
 # Hello World
-</source>
+</syntaxhighlight>
+<syntaxhighlight lang='Bash'>
+greeting="Hello World"
+r1="greet"
+r2="ing"
+eval echo \$"$r1$r2"
+</syntaxhighlight>
 ==PHP==
 [[category: PHP]]
-<source lang='PHP'>
+<syntaxhighlight lang='PHP'>
+$greeting = "Hello World";
+$ref= "greeting";
+echo $$ref;
+// Hello World
+</syntaxhighlight>
+<syntaxhighlight lang='PHP'>
 $greeting = "Hello World";
-$variable_name = "greeting";
+$r1 = "greet";
-echo $$variable_name;
+$r2 = "ing";
+echo ${$r1.$r2};
 // Hello World
-</source>
+</syntaxhighlight>